Contraception As virtually all of our animals are housed socially, considerable effort has continued to be invested in contraception to prevent new pregnancies. To continue observation of menstrual cyclicity, we have chosen IUDs as the primary method of contraception. Thus far, with over 508 cycles of breeding exposure, we have observed three pregnancies and only one clinical problem migration of an IUD from the uterus into the bladder). This is a 0.6% failure rate, in keeping with that predicted from human use. The expected life of the IUD is at least 5 years. Placement is monitored by direct visualization, ultrasound, or x-ray at time of routine clinical survey. In addition, several females within the breeding cohort have been implanted with Norplant and 6 males have undergone vas ligation. To date, DNA has been collected from 124 chimpanzees using the Puregene kit. This is an ongoing process that includes genotyping by Dr. Stone and his staff at Trinity Univ ersity as required for colony management. Standard Operating Procedures have been written and implemented for carestaff to assist in enrichment duties at the Main Center. In addition, the Emory Policy on Environmental Enrichment for Nonhuman Primates has been updated to reflect recent elaborations to the program, and an extensive bibliography has been attached for training purposes. In the next year, we intend to maintain strict limits on chimpanzee breeding and to continue to focus on improving the management of our chimpanzee colony. These plans include use of positive reinforcement training vs. unstructured human interaction as enrichment for chimpanzees housed in indoor-outdoor runs; documentation of the course and success of social introductions and introduction of new projects involving joystick-controlled computer video tasks as enrichment. FUNDING NIH / RR03591 $417,694 9/01/95 - 8/31/00 PUBLICATIONS Gould, K.G. Use of IUDs as a management tool for the chimpanzee (Pan troglodytes). J. Med. Primatol. (In press). P51RR00165-38 1/1/98 - 12/31/98 Yerkes Regional Primate Research Center